Take a look at https://revenium.io https://revenium.io (full disclosure: I'm co-founder/cto.) We are a fully hosted solution with a free/developer tier and plan

Take a look at https://revenium.io https://revenium.io (full disclosure: I'm co-founder/cto.) We are a fully hosted solution with a free/developer tier and plans that start at $19/month. We also have a self-hosted option.